Gas turbine engines operate to produce mechanical work or thrust. Specifically, land-based gas turbine engines typically have a generator coupled thereto for the purposes of generating electricity. A gas turbine engine comprises an inlet that directs air to a compressor section, which has stages of rotating compressor blades. As the air passes through the compressor, the pressure of the air increases. The compressed air is then directed into one or more combustors where fuel is injected into the compressed air and the mixture is ignited. The hot combustion gases are then directed from the combustion section to a turbine section by a transition duct. The hot combustion gases cause the stages of the turbine to rotate, which in turn, causes the compressor to rotate.
The air and hot combustion gases are directed through a compressor and turbine section, respectively, by compressor blades/vanes and turbine blades/vanes. These blades and vanes are subject to steady-state and vibratory stresses due to the thermal and mechanical loads applied to the airfoil surface. The blades and vanes often have at least one region where the airfoil section transitions to a wall portion, often referred to as a platform, that maintains an inner or outer air path. The transition between an airfoil and a platform can be a region of sharp geometry change that can further increase areas of high stress already present due to the thermal and mechanical stresses present.